Fall Tips for your Pond Plants

Temperatures are dipping and the days are shortening. As you say goodbye to the long sunny days of summer, it's time to turn your attention to the plants in and around your pond to make sure they're ready to face the first frost.Hardy MarginalsAs with terrestrial perennial plants, dropping temperatures alert your hardy aquatic plants to prepare for their winter dormancy. You should stop fertilizing them as you see leaves begin to yellow and brown. It's ok to leave these plants where they are in your pond to weather the cold of winter, just be sure to trim the dying foliage of your marginal plants down to 2" above the water level. Remove any excess plant material as needed.Tropical MarginalsWater gardeners who live in our colder zones will need to treat these plants as they would any garden annual by replacing them each season. A fun alternative is to treat them as tropical houseplants and bring them in for the winter. Most tropical marginals will do well potted in heavy garden soil in a sealed clay pot with no drainage holes. When kept wet, the plants do well in a sunny window or sunroom. Come springtime, you can replant them back in the pond and see what happens.Water LiliesWater lilies will also begin to show their dislike for the cold with yellowing leaves and fewer flowers. Trim off the mature leaves a few inches above the crown and drop the pot to the lowest depth of the pond. If your water lilies are permanently planted in pockets at the lowest part of your pond, all you need to do is remove the dead foliage. Hardy water lilies need to have a period of dormancy which is onset by cold water, so do not bring then into a heated indoor pond to keep them growing. Tropical water lilies will flower up to and past the first light frost as they have no idea what winter is and no need to prepare for it. Tropical water lilies can be over-wintered indoors in water over 50 degrees F, or they can be taken out of the pot and stored in moist sand. The warm water method isn't practical for most, and success with the moist sand method is variable, usually ending in the loss of the tuber to mold or rot. Botanical gardens with trained horticulturists expect to lose many of the tropical water lilies they store every winter. Start over each year as you do with flats of annuals.LotusAs with the marginals in your pond, the foliage of your lotus plants will need to be trimmed back after they have died back and turned brown. It's important not to cut the leaves while they are still green because freshly cut, hollow stems are susceptible to disease which can then spread to the plant's tuber, possibly killing the plant. Lotus tubers will not withstand freezing, so any plants that are growing in the shallow areas of your pond should be moved to the deepest part of your pond, away from freezing water. When you take the time to care for your aquatic plants in the fall you'll have less work ahead of you in the spring and healthier plants will emerge from their winter's nap.